Biomes & Biodiversity Conservation: Complete Ecology Notes

Biomes • Biodiversity • Biogeography • Biodiversity Status • Biodiversity in India • Biodiversity Loss • Invasive Species • Conservation Strategies

CSIR-NET • GATE • DBT-BET • ICMR-JRF • MSc Biotechnology

Study Tip: Biomes and biodiversity are closely connected concepts in ecology. A biome represents a large ecological region characterized by particular climate, vegetation and associated organisms, whereas biodiversity describes the variety of life at genetic, species and ecosystem levels. For competitive examinations, remember the logical sequence: Climate → Biome → Habitat → Species → Biodiversity → Human impacts → Biodiversity loss → Conservation

1. Introduction to Biomes and Biodiversity

The Earth contains an enormous variety of organisms distributed across different geographical regions. These organisms do not occur randomly. Their distribution is strongly influenced by climate, temperature, precipitation, soil, topography, availability of water, evolutionary history and interactions with other organisms.

Large geographical regions that share broadly similar climatic conditions, vegetation characteristics and associated animal communities are commonly described as biomes. Forests, grasslands, deserts and tundra represent major terrestrial biome types.

Within these biomes, different habitats support different species. The variety of organisms found within a region is described as its biodiversity.

Biodiversity includes variation among genes, species and ecosystems. Therefore, biodiversity is much broader than simply counting the number of species in an area.

Key Concept: Biome describes a large ecological region, while biodiversity describes the variety and variability of living organisms occurring within ecosystems, regions and the planet as a whole.

2. What is a Biome?

A biome is a major ecological region characterized by a particular combination of climate, dominant vegetation and associated organisms. Biomes are usually much larger than individual ecosystems and may cover extensive geographical areas.

Climate is one of the strongest factors determining the characteristics of terrestrial biomes. In particular, temperature and precipitation influence plant growth, primary productivity, decomposition and the types of animals that can survive in a region.

Characteristics of a biome

Large geographical extent: Biomes generally cover large regions and may cross political boundaries.
Characteristic climate: Temperature and precipitation strongly influence biome structure.
Dominant vegetation: Particular plant growth forms often characterize a biome.
Characteristic fauna: Animals are adapted to the climate, vegetation and available resources.
Environmental adaptations: Organisms possess structural, physiological and behavioural features suited to their environments.

Biome vs Ecosystem

Feature	Biome	Ecosystem
Scale	Very large geographical region	Usually smaller ecological unit
Main defining features	Climate and dominant vegetation	Biotic and abiotic interactions
Examples	Desert, tundra, tropical rainforest	Pond, lake, forest patch
Species composition	Broad characteristic groups	Specific local community

3. Factors Determining Biome Distribution

The distribution of terrestrial biomes is controlled by several interacting environmental factors. Temperature and precipitation are particularly important because they influence plant productivity and water availability.

🌡 Temperature

Temperature affects metabolic activity, photosynthesis, plant growth, decomposition and survival.

🌧 Precipitation

Rainfall determines water availability and strongly influences vegetation density and productivity.

🌍 Latitude

Latitude influences solar radiation, temperature and seasonality.

⛰ Altitude

Altitude modifies temperature, atmospheric pressure and precipitation, producing vegetation changes along elevation gradients.

🌱 Soil

Soil texture, pH, nutrients, moisture and organic matter influence plant growth.

💧 Water Availability

Availability of surface and soil water strongly determines vegetation composition.

Climate–Vegetation relationship

Climate and vegetation show a strong relationship. Regions receiving sufficient rainfall and having suitable temperatures can support dense vegetation, while regions with limited precipitation tend to support vegetation adapted to water scarcity.

4. Major Terrestrial Biomes

Terrestrial biomes are broadly categorized according to climate and dominant vegetation. Major terrestrial biome types include tropical forests, temperate forests, boreal forests, grasslands, deserts and tundra.

Biome	Climate	Typical vegetation	Important features
Tropical rainforest	Warm and wet	Dense evergreen vegetation	Very high biodiversity and productivity
Savanna	Warm with seasonal rainfall	Grasses with scattered trees	Seasonal drought and frequent fire
Temperate grassland	Moderate rainfall, seasonal climate	Dominant grasses	Often fertile soils
Desert	Very low precipitation	Xerophytic vegetation	Water limitation
Temperate forest	Moderate temperature and rainfall	Deciduous or mixed forests	Strong seasonality
Boreal forest	Cold climate	Coniferous trees	Long winters
Tundra	Very cold	Mosses, lichens and dwarf plants	Permafrost in many areas

5. Forest Biomes

Forests are terrestrial ecosystems dominated by trees. They occur under different climatic conditions and therefore show considerable variation in structure, productivity and species composition.

Tropical Rainforest

Tropical rainforests generally occur in warm regions receiving high amounts of precipitation. They are characterized by complex vegetation layers, including emergent trees, canopy, understory and forest floor.

High species richness.
High primary productivity.
Complex vertical structure.
Warm temperatures throughout much of the year.
High rainfall.
Rapid decomposition under favourable conditions.
Large numbers of plant, animal, fungal and microbial species.

Temperate Forest

Temperate forests occur in regions with stronger seasonal variation in temperature. Deciduous trees may shed their leaves during particular seasons, while evergreen species retain foliage.

Boreal Forest or Taiga

Boreal forests occur mainly at high northern latitudes. They are dominated by coniferous trees and experience long cold winters.

Exam Point: Tropical forests generally support very high biodiversity because warm temperatures, substantial rainfall and long growing seasons create conditions favourable for high biological productivity and diversification.

6. Grassland Biomes

Grasslands are ecosystems in which grasses and herbaceous plants form a major component of the vegetation. Trees may be sparse or absent depending on rainfall, fire, grazing and soil conditions.

Major grassland types

Tropical grasslands: commonly associated with seasonal rainfall and scattered trees.
Temperate grasslands: generally experience seasonal temperature changes and are often dominated by grasses.

Ecological importance of grasslands

Support large herbivore populations.
Store substantial amounts of carbon in soils.
Provide habitat for insects, birds and mammals.
Support nutrient cycling.
Provide grazing resources.
Can have highly productive soils.

Fire and grazing can play important ecological roles in maintaining many grassland systems. Some grassland species have adaptations that allow them to survive periodic fires or grazing.

7. Desert Biomes

Deserts are characterized primarily by low precipitation. They can occur in hot or cold regions. The major ecological challenge is generally water availability rather than temperature alone.

Adaptations of desert plants

Reduced leaf area.
Thick cuticle.
Water-storage tissues.
Deep or extensive root systems.
Stomatal regulation.
CAM photosynthesis in many succulent plants.
Spines or modified leaves in some species.

Adaptations of desert animals

Nocturnal activity.
Burrowing behaviour.
Efficient water conservation.
Reduced exposure to extreme daytime temperatures.
Physiological mechanisms for maintaining water balance.

Important: Deserts are not necessarily biologically empty. Many deserts contain specialized organisms with adaptations that allow survival under severe water limitation.

8. Tundra Biome

Tundra is a cold biome characterized by low temperatures, short growing seasons and limited tree growth. In Arctic tundra, permanently or seasonally frozen ground can strongly influence ecosystem processes.

Typical vegetation

Mosses.
Lichens.
Grasses.
Sedges.
Dwarf shrubs.

Major ecological characteristics

Low temperatures.
Short growing season.
Low decomposition rates during cold periods.
Low tree abundance.
Strong seasonal variation.
Specialized cold-adapted organisms.

9. Aquatic Biomes

Aquatic biomes are broadly divided into freshwater and marine systems. Water availability is not the limiting issue in the same way as in terrestrial deserts, but factors such as salinity, temperature, dissolved oxygen, light penetration, nutrients and water movement strongly influence aquatic life.

Freshwater ecosystems

Lakes.
Ponds.
Rivers.
Streams.
Wetlands.

Marine ecosystems

Oceans.
Coral reefs.
Estuaries.
Mangrove ecosystems.
Coastal ecosystems.

System	Major factor	Examples of organisms
Freshwater	Low salinity	Fish, algae, aquatic plants, invertebrates
Marine	Higher salinity	Marine fish, algae, corals, mammals
Estuary	Variable salinity	Fish, crustaceans, molluscs, mangroves
Wetland	Waterlogged conditions	Birds, amphibians, plants, microorganisms

10. Meaning of Biodiversity

The term biodiversity refers to the variety and variability of living organisms. It includes variation within species, variation among species and variation among ecosystems.

Biodiversity is therefore a multidimensional concept. Species richness is only one component of biodiversity.

Why is biodiversity important?

Maintains ecosystem functioning.
Supports food production.
Provides medicinal resources.
Supports pollination.
Contributes to nutrient cycling.
Supports soil formation.
Helps regulate climate.
Provides genetic resources for agriculture.
Supports cultural and recreational values.
Improves ecosystem resilience.

Species Richness

Number of species present in a particular area.

Species Evenness

Relative abundance of different species within a community.

Genetic Diversity

Variation in genes and alleles within and among populations.

Ecosystem Diversity

Variety of ecosystems, habitats and ecological processes in a region.

11. Levels of Biodiversity

1. Genetic Diversity

Genetic diversity refers to variation in genetic composition among individuals and populations of the same species. It provides the raw material for adaptation and evolutionary change.

For example, different varieties of rice, wheat or other crops may contain different genetic characteristics such as drought tolerance, disease resistance or salinity tolerance.

2. Species Diversity

Species diversity refers to the variety of species within a community or region. It incorporates both species richness and relative abundance.

3. Ecosystem Diversity

Ecosystem diversity refers to the variety of ecosystems and habitats within a geographical region. Forests, grasslands, wetlands, deserts, rivers and coastal ecosystems represent different ecosystem types.

12. Global Status of Biodiversity

Global biodiversity is under significant pressure from human activities. Many species and ecosystems are experiencing population declines, habitat degradation and increasing threats.

Biodiversity change occurs at different scales. A population may decline without immediately becoming extinct, while habitat degradation can reduce the ability of species to survive and reproduce.

Major global trends

Habitat destruction and fragmentation are major threats.
Overexploitation affects many wild populations.
Invasive alien species can alter native communities.
Pollution can affect terrestrial and aquatic ecosystems.
Climate change is modifying environmental conditions.
Genetic diversity can decline when populations become small and isolated.
Species extinction permanently removes biological diversity.

Important: Biodiversity loss does not mean only extinction. It can also involve population declines, habitat loss, reduced genetic diversity, community simplification and degradation of ecosystem functions.

13. Biogeography

Biogeography is the study of the geographical distribution of organisms through space and time. It combines ecological and evolutionary perspectives to understand why species occur where they do.

Major components of biogeography

Ecological biogeography: focuses on how environmental conditions influence present-day species distributions.
Historical biogeography: examines how evolutionary history, geological events and historical processes have shaped distribution.

Factors influencing species distribution

Climate.
Temperature.
Rainfall.
Water availability.
Soil.
Topography.
Geological history.
Dispersal ability.
Competition.
Predation.
Evolutionary history.
Human activities.

Biogeography is important for conservation because conservation priorities depend strongly on where species occur, how restricted their ranges are and how their habitats are changing.

14. Patterns of Species Distribution

Species distribution refers to the geographical areas occupied by a species. Some species have very broad distributions, whereas others are restricted to particular geographical regions.

Endemic species

An endemic species is a species naturally restricted to a particular geographical region. Endemism is important in conservation because species with restricted ranges may be especially vulnerable to habitat loss.

Cosmopolitan distribution

Species with very broad geographical distributions are sometimes described as cosmopolitan. Such species may occur across multiple continents or environmental regions.

Disjunct distribution

A disjunct distribution occurs when populations of a species are separated geographically by large distances or unsuitable habitat.

Exam Point: High endemism combined with severe habitat pressure is an important reason why certain regions become conservation priorities.

15. Status of Biodiversity in India

India is recognized as one of the biologically diverse countries of the world. Its geographical position, wide range of climates, varied topography and large number of habitat types contribute to its biodiversity.

India contains ecosystems ranging from Himalayan mountains and alpine habitats to tropical forests, grasslands, deserts, wetlands, mangroves, coastal ecosystems and marine habitats.

Major reasons for India's biodiversity

Large geographical area.
Wide latitudinal range.
Major differences in altitude.
Monsoon-driven climate variability.
Himalayan and other mountain systems.
Long coastline.
Islands with unique habitats.
Variety of soil types.
Multiple biogeographic regions.
Long evolutionary history.

16. Biodiversity in India

India supports substantial plant, animal, fungal and microbial diversity. Different regions contain distinct ecological communities because of differences in climate, elevation, geology and habitat structure.

Examples of important ecosystems in India

🏔 Himalayas

High-altitude ecosystems, alpine vegetation, forests and diverse fauna.

🌳 Tropical Forests

High productivity and species-rich communities occur in suitable warm and wet regions.

🏜 Deserts

Specialized organisms adapted to low precipitation and temperature extremes.

🌊 Coastal Ecosystems

Mangroves, estuaries, mudflats and marine ecosystems support diverse life.

🐠 Coral Reefs

Highly productive and structurally complex marine habitats.

🌾 Grasslands

Important habitats for herbivores, birds, insects and grassland plants.

17. India as a Megadiverse Country

India is included among the world's megadiverse countries. The concept of megadiverse countries recognizes nations that contain exceptionally high levels of biological diversity and often significant levels of endemism.

India's biodiversity is strongly associated with its ecological and geographical heterogeneity. Mountains, plateaus, plains, deserts, forests, wetlands, islands and marine systems create numerous ecological niches.

Why megadiversity matters

High biological richness creates major ecological value.
Endemic species may have restricted geographical ranges.
Genetic resources can support agriculture and biotechnology.
Ecosystems provide important ecosystem services.
Conservation of biodiversity supports long-term ecological stability.

18. Biodiversity Hotspots of India

A biodiversity hotspot is a region recognized for high levels of endemic species combined with substantial habitat loss or threat. The hotspot concept helps identify regions where conservation efforts can have high priority.

Four global biodiversity hotspots extend into India:

Himalaya
Indo-Burma
Western Ghats–Sri Lanka
Sundaland — represented in India primarily by the Nicobar Islands.

Hotspot	Indian region	Important features
Himalaya	Indian Himalayan region	Altitude gradients, diverse forests and high endemism
Indo-Burma	Parts of northeastern India	High species diversity and threatened habitats
Western Ghats–Sri Lanka	Western Ghats	High endemism and species-rich ecosystems
Sundaland	Nicobar Islands	Island biodiversity and endemic species

Exam Point: Do not confuse a biodiversity hotspot with a biodiversity-rich region alone. The hotspot concept also emphasizes the degree of habitat loss or threat.

19. Loss of Biodiversity

Biodiversity loss refers to reduction in biological diversity at genetic, species or ecosystem levels. It can occur through species extinction, population decline, habitat destruction, genetic erosion and ecosystem degradation.

Major consequences

Loss of ecosystem functions.
Reduction in ecosystem resilience.
Loss of genetic resources.
Decline in pollination services.
Disruption of food webs.
Loss of medicinal and economically valuable species.
Reduction in soil and water ecosystem services.
Increased vulnerability of ecosystems to environmental change.

20. Major Causes of Biodiversity Loss

1. Habitat Loss

Habitat loss occurs when natural habitats are converted into agricultural land, cities, roads, industries, dams or other human-dominated landscapes. It is one of the most important drivers of biodiversity decline.

2. Habitat Fragmentation

Fragmentation divides continuous habitat into smaller isolated patches. This can reduce population size, restrict movement and increase edge effects.

3. Overexploitation

Overexploitation occurs when organisms are harvested faster than populations can recover. Examples include overfishing, excessive hunting and unsustainable collection of wild plants.

4. Pollution

Air, water and soil pollution can directly or indirectly harm organisms. Examples include pesticides, industrial pollutants, plastics, nutrient pollution and toxic metals.

5. Climate Change

Climate change can alter temperature, rainfall, sea level, fire regimes and the timing of ecological events. Species may need to shift their ranges or adapt to changing conditions.

6. Invasive Alien Species

Non-native species that establish and spread can compete with native species, alter habitats and modify ecosystem processes.

Driver	Major effect
Habitat loss	Reduction or disappearance of suitable habitat
Fragmentation	Isolation of populations and increased edge effects
Overexploitation	Population decline due to excessive harvesting
Pollution	Toxic or physiological stress
Climate change	Changes in environmental conditions and species ranges
Invasive species	Competition, predation and ecosystem modification

21. Invasive Species

An invasive alien species is a non-native organism that establishes and spreads in a new environment and causes ecological, economic or social impacts.

Not every introduced species becomes invasive. A species must successfully establish, reproduce and spread, and significant negative impacts are often associated with invasive status.

General invasion process

22. Important Invasive Species in India

India has several introduced plant and animal species that have become ecologically important. Some invasive plants spread rapidly in disturbed habitats and can suppress native vegetation.

Species	Common name	Major concern
Parthenium hysterophorus	Congress grass / carrot grass	Invades disturbed habitats and affects native vegetation
Lantana camara	Lantana	Forms dense thickets and interferes with native vegetation
Prosopis juliflora	Mesquite	Can transform dryland habitats and compete with native plants
Eichhornia crassipes	Water hyacinth	Can form dense mats in freshwater systems
Chromolaena odorata	Siam weed	Rapid spread and competition with native plants

Ecological impacts of invasive species

Competition with native species.
Reduction in native plant diversity.
Modification of nutrient cycling.
Alteration of fire regimes.
Changes in water availability.
Modification of habitat structure.
Potential economic losses.

23. Biodiversity Conservation

Biodiversity conservation refers to the protection, management and sustainable use of biological diversity. Conservation aims to prevent extinction, maintain ecosystems, preserve genetic resources and ensure that biological resources remain available for future generations.

Main objectives

Protect species from extinction.
Maintain genetic diversity.
Protect habitats and ecosystems.
Maintain ecological processes.
Promote sustainable use of biological resources.
Control invasive species.
Restore degraded ecosystems.
Support local communities and sustainable livelihoods.

24. In-situ Conservation

In-situ conservation means conserving organisms within their natural habitats. It allows populations to continue interacting with their environment and with other organisms.

Examples

National parks.
Wildlife sanctuaries.
Biosphere reserves.
Community conservation areas.
Protected forests.
Marine protected areas.

Advantages

Protects entire ecosystems.
Maintains natural ecological interactions.
Allows natural evolutionary processes to continue.
Protects multiple species simultaneously.
Preserves habitat and associated ecological processes.

25. Ex-situ Conservation

Ex-situ conservation involves conserving organisms outside their natural habitats. It is especially useful when wild populations are critically small or when species require controlled conditions for survival and propagation.

Examples

Botanical gardens.
Zoos.
Seed banks.
Gene banks.
Field gene banks.
Tissue culture collections.
Cryopreservation.
Captive breeding programmes.

Cryopreservation

Cryopreservation involves long-term preservation of biological materials at very low temperatures. Depending on the material, liquid nitrogen is widely used for maintaining cells, tissues, embryos, gametes or genetic resources.

Feature	In-situ	Ex-situ
Location	Natural habitat	Outside natural habitat
Examples	National parks, sanctuaries	Zoos, seed banks
Ecosystem protection	High	Limited
Natural interactions	Maintained	Usually controlled
Use	Habitat and population conservation	Genetic resource and species conservation

26. Protected Areas

Protected areas are geographically defined regions managed for conservation of biodiversity and associated ecological values.

National Parks

National parks are protected areas established primarily for conservation of wildlife and natural ecosystems. Human activities are generally more restricted than in many other categories of protected areas.

Wildlife Sanctuaries

Wildlife sanctuaries are protected areas intended primarily for conservation of wildlife and habitats. The specific regulations governing human activities can differ among areas.

Biosphere Reserves

Biosphere reserves are large areas designed to promote conservation of biodiversity together with sustainable use and research. They commonly include zones with different levels of protection and human activity.

Protected area type	Primary emphasis
National Park	Protection of ecosystems and wildlife
Wildlife Sanctuary	Wildlife and habitat conservation
Biosphere Reserve	Conservation + sustainable development + research

27. Biodiversity Conservation in India

India has developed a legal and institutional framework for biodiversity conservation. Several laws and programmes support wildlife protection, forest conservation and sustainable use of biological resources.

Biological Diversity Act

The Biological Diversity Act, 2002 provides an important legal framework for conservation of biological diversity, sustainable use of biological resources and fair and equitable sharing of benefits arising from the use of biological resources and associated knowledge.

Wildlife Protection Act

The Wild Life (Protection) Act, 1972 provides a legal framework for protection of wild animals, birds and plants and supports the establishment and management of protected areas.

Forest Conservation Framework

Forest-related laws and policies regulate diversion of forest land and support conservation of forest ecosystems.

Exam Focus: Remember the three broad goals associated with biodiversity conservation:

1. Conservation of biological diversity
2. Sustainable use of biological resources
3. Fair and equitable sharing of benefits

28. Modern Strategies for Biodiversity Conservation

Habitat Restoration

Restoration attempts to recover ecological structure, function and biodiversity in degraded ecosystems. Restoration may involve reforestation, wetland restoration, removal of invasive species and recovery of native vegetation.

Wildlife Corridors

Wildlife corridors connect fragmented habitat patches and facilitate movement of organisms between populations. They can reduce isolation and support gene flow.

Community-Based Conservation

Local communities often possess ecological knowledge and directly depend on natural resources. Conservation programmes can be more effective when local communities participate in planning, management and benefit sharing.

Seed Banks and Gene Banks

Seed banks and gene banks preserve genetic resources for future research, breeding and restoration programmes.

Environmental Education

Education increases awareness about biodiversity, sustainable resource use, wildlife protection and ecosystem conservation.

29. Quick Revision Notes

⭐ Must-Remember Points

A biome is a large ecological region characterized by climate and dominant vegetation.
Temperature and precipitation are major determinants of terrestrial biome distribution.
Tropical rainforests generally show very high biological productivity and species richness.
Grasslands are characterized by dominance of grasses and herbaceous plants.
Deserts are primarily characterized by low precipitation.
Tundra is characterized by very low temperatures and short growing seasons.
Aquatic biomes include freshwater and marine systems.
Biodiversity includes genetic, species and ecosystem diversity.
Species richness is the number of species in an area.
Species evenness describes the relative abundance of species.
Biogeography studies geographical distribution of organisms through space and time.
Endemic species are naturally restricted to a particular geographical area.
India is one of the world's megadiverse countries.
India contains four global biodiversity hotspots: Himalaya, Indo-Burma, Western Ghats–Sri Lanka and Sundaland.
Biodiversity loss includes population decline, habitat loss, genetic erosion and extinction.
Habitat destruction and fragmentation are major drivers of biodiversity loss.
Overexploitation can cause rapid population decline.
Pollution can directly or indirectly damage organisms and ecosystems.
Climate change can alter species ranges and ecosystem processes.
Invasive alien species are non-native organisms that establish and spread and can produce ecological impacts.
Not every introduced species becomes invasive.
Parthenium hysterophorus, Lantana camara and Eichhornia crassipes are important invasive species associated with India.
In-situ conservation protects organisms in their natural habitats.
Ex-situ conservation protects organisms or genetic material outside natural habitats.
National parks and wildlife sanctuaries are examples of protected areas.
Biosphere reserves combine conservation with sustainable development and research.
Seed banks and gene banks are important ex-situ conservation tools.
Wildlife corridors can reduce habitat fragmentation and improve connectivity.
The Biological Diversity Act, 2002 provides an important framework for biodiversity conservation in India.
Sustainable use is an important component of biodiversity management.

30. Important Comparisons for Competitive Exams

Concept	Meaning	Easy clue
Biome	Large ecological region with characteristic climate and vegetation	Large ecological zone
Habitat	Place where an organism lives	Address of organism
Biodiversity	Variety and variability of life	Genes + species + ecosystems
Genetic diversity	Variation within and among populations of a species	Genes
Species diversity	Variety and abundance of species	Species
Ecosystem diversity	Variety of ecosystems and habitats	Ecosystems
Biogeography	Study of geographical distribution of organisms	Where organisms occur
Endemic species	Restricted naturally to a particular region	Limited range
Invasive species	Non-native species that establishes and causes impacts	Introduced + spread + impact
In-situ conservation	Conservation in natural habitat	Protect habitat
Ex-situ conservation	Conservation outside natural habitat	Seed bank / zoo
Species richness	Number of species present	How many?
Species evenness	Relative abundance of species	How evenly distributed?

31. Important Biodiversity Terms

Biodiversity

Variety and variability of living organisms at genetic, species and ecosystem levels.

Biome

Large ecological region characterized by climate and dominant vegetation.

Biogeography

Study of geographical distribution of organisms through space and time.

Endemism

Occurrence of a species naturally restricted to a particular geographical region.

Hotspot

Region with high endemic biodiversity and substantial habitat loss or threat.

Invasive Species

Non-native species that establishes, spreads and causes ecological or other negative impacts.

In-situ Conservation

Conservation of species within their natural habitats.

Ex-situ Conservation

Conservation of species or genetic material outside natural habitats.

33. Final Exam-Oriented Summary

Biomes and biodiversity are fundamental concepts in ecology and environmental biology. A biome is a large ecological region characterized by climate and dominant vegetation, while biodiversity describes the variety and variability of life.

Biomes: large ecological regions influenced strongly by temperature and precipitation.
Forest biomes: include tropical, temperate and boreal forests.
Grasslands: dominated mainly by grasses and herbaceous vegetation.
Deserts: characterized primarily by low precipitation and specialized drought adaptations.
Tundra: cold biome with short growing seasons and limited tree growth.
Biodiversity: includes genetic, species and ecosystem diversity.
Biogeography: studies geographical distribution of organisms through space and time.
India: is a megadiverse country with numerous ecosystems, high species richness and significant endemism.
Indian biodiversity hotspots: Himalaya, Indo-Burma, Western Ghats–Sri Lanka and Sundaland.
Biodiversity loss: includes habitat loss, fragmentation, population decline, genetic erosion and extinction.
Major drivers: habitat destruction, overexploitation, pollution, climate change and invasive species.
Invasive species: non-native organisms that establish, spread and cause ecological or other negative impacts.
In-situ conservation: conservation in the natural habitat.
Ex-situ conservation: conservation outside the natural habitat.
Protected areas: national parks, wildlife sanctuaries and biosphere reserves are important conservation approaches.
Genetic conservation: seed banks, gene banks and cryopreservation can preserve valuable genetic resources.
Habitat corridors: improve connectivity among fragmented habitats.
Restoration: aims to recover ecological structure, function and biodiversity in degraded ecosystems.

For CSIR-NET, GATE Biotechnology, DBT-BET, ICMR-JRF and MSc Biotechnology examinations, pay special attention to the differences between biome and ecosystem, species richness and species evenness, genetic/species/ecosystem diversity, endemic and invasive species, in-situ and ex-situ conservation, and habitat loss versus fragmentation.

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Friday, 28 August 2026